Delaying second Pfizer vaccines to 12 weeks significantly increases antibody responses in older people

A study (preprint, not yet peer reviewed) of 175 people aged ≥80 found that those given the second dose of the Pfizer Covid-19 vaccine after 12 weeks had a 3.5-fold higher peak SARS-CoV-2 spike specific antibody response than those who had the second dose after 3 weeks.

University of Birmingham